The gasifier

The heart of the wood gasification CHP plant is the downdraft fixed bed gasifier. The process by which biomass is converted into gas uses various thermo-chemical reactions : pyrolysis, oxidation, reduction.

The wood is reduced to ashes that represent about 1% of the initial wood mass. The main output is a gas mainly composed of hydrogen (H2) and carbon monoxide (CO). This fuel gas presents a low calorific value (LCV) between 4.5 and 5.8 MJ/Nm3, which suit standard engines perfectly well.

The conversion efficiency of the downdraft fixed bed gasifier reaches 70% to 85%.